我已经尝试创建一个 ARView 两天多了，它可以随时间记录相机在空间中的位置，然后将其保存到关键帧文件中。基本上，我想创建一个应用程序，让您记录虚拟相机的运动，然后可以在 3D 应用程序中使用，例如Autodesk Maya or Cinema4D驱动相机。首选文件输出是任何可以容纳相机对象并随时间对其进行动画处理的东西（或者也可以是随时间移动的对象，然后我可以将相机作为其父对象）。
这是我的代码，抱歉它有点混乱，我尝试了很多不同的东西...基本上我尝试记录设备位置和旋转，然后将其保存到 MDL 对象，但不知何故它没有动画。我还尝试了多种不同的文件类型（其中一些不支持关键帧动画，所以这没有帮助，但据我了解，Alembic 可以）
import SwiftUI
import ARKit
import RealityKit
import ModelIO
struct ARViewContainer: UIViewRepresentable {
let session = ARSession()
let delegate = MySessionDelegate()
func makeUIView(context: Context) -> ARView {
// Set up the ARView with session
let arView = ARView(frame: .zero)
let boxAnchor = try! Experience.loadBox()
arView.scene.anchors.append(boxAnchor)
arView.session.delegate = delegate // assign delegate to the session
return arView
}
func updateUIView(_ uiView: ARView, context: Context) {
// Update the ARView if needed
}
func startARSession() {
// Start the ARSession
let configuration = ARWorldTrackingConfiguration()
configuration.planeDetection = [.horizontal, .vertical]
session.run(configuration, options: [])
}
func stopARSession() {
// Stop the ARSession
session.pause()
}
}
class MySessionDelegate: NSObject, ARSessionDelegate {
var object: MDLMesh?
let asset = MDLAsset()
let cameraTransform = MDLTransform()
var documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
func session(_ session: ARSession, didUpdate frame: ARFrame) {
// Get the camera position and orientation for the current frame
let transform = frame.camera.transform
let rotation = frame.camera.eulerAngles
let position = transform.columns.3
let elapsedTime = frame.timestamp
cameraTransform.setTranslation(position[SIMD3(0,1,2)], forTime: elapsedTime)
cameraTransform.setRotation(rotation, forTime: elapsedTime)
print("Camera Transform: \(cameraTransform.matrix)")
}
}
struct Camera: View {
var body: some View {
VStack {
ARViewContainer().onAppear(perform: ARViewContainer().startARSession)
.onDisappear(perform: ARViewContainer().stopARSession)
Button("Export Recording") {
// Create an MDLAsset with a box representing the camera transform
let object = MDLMesh(boxWithExtent: .init(0.1, 0.1, 0.1), segments: .init(10, 10, 10), inwardNormals: false, geometryType: .triangles, allocator: nil)
object.name = "Camera Transform"
object.transform = MySessionDelegate().cameraTransform
let asset = MDLAsset()
asset.add(object)
// Export the MDLAsset to a file
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let fileURL = documentsDirectory.appendingPathComponent("recording.abc")
try! asset.export(to: fileURL)
}
}
}
}
如果有完全不同的方法，也请分享，我先感谢大家的帮助！
写一个4x4 变换矩阵（即存储平移、旋转和缩放的复杂变换）到文本文件，我使用write(to:)实例方法。点击后Record Transform Values按钮，数据立即开始写入toMaya.txt文件。为了方便起见，我将矩阵的所有 16 个值都放在屏幕上（我在 iPad 上测试了这一点，因此请使用屏幕更大的设备）。再次按下该按钮将停止录制。
数据来自嵌套列表 in the toMaya.txt可以使用常规 Python 或 MEL 脚本轻松读取文件。看看嵌套是什么样子的。每一个16 个矩阵值在Float type.
[x0,y0,z0,w0]是第一个矩阵列，[x1,y1,z1,w1]是第二个矩阵列，等等。
这是代码：
import SwiftUI
import RealityKit
import Combine
struct ARViewContainer : UIViewRepresentable {
@Binding var arView: ARView
func makeUIView(context: Context) -> ARView { return arView }
func updateUIView(_ view: ARView, context: Context) { }
}
struct ContentView : View {
@State private var arView = ARView(frame: .zero)
@State private var subs: [AnyCancellable] = []
@State private var array: [[[Float]]] = [[ [1,0,0,0], [0,1,0,0],
[0,0,1,0], [0,0,0,1] ]]
@State private var boolean = false
let url = FileManager.default.urls(for: .documentDirectory,
in: .userDomainMask)[0]
.appendingPathComponent("toMaya.txt")
var body: some View {
ZStack {
ARViewContainer(arView: $arView).ignoresSafeArea()
VStack {
Button("Record Transform Values") {
boolean.toggle()
DispatchQueue.main.async {
arView.scene.subscribe(to: SceneEvents.Update.self) { _ in
let col = arView.cameraTransform.matrix.columns
let mtx: [[Float]] = [
[col.0.x, col.0.y, col.0.z, col.0.w],
[col.1.x, col.1.y, col.1.z, col.1.w],
[col.2.x, col.2.y, col.2.z, col.2.w],
[col.3.x, col.3.y, col.3.z, col.3.w]
]
if boolean {
array.append(mtx)
}
if let data = try? JSONEncoder().encode(self.array) {
guard let str = String(data: data, encoding: .ascii)
else { return }
do {
if boolean {
try str.write(to: url, atomically: true,
encoding: .ascii)
}
} catch {
print(error.localizedDescription)
}
print(url)
}
}.store(in: &subs)
}
}
Spacer()
}
VStack {
Spacer()
Text("\(array.count)").foregroundColor(.white)
}
HStack {
VStack {
Text("\(array.last![0][0])").foregroundColor(.white)
Text("\(array.last![0][1])").foregroundColor(.white)
Text("\(array.last![0][2])").foregroundColor(.white)
Text("\(array.last![0][3])").foregroundColor(.white)
}
VStack {
Text("\(array.last![1][0])").foregroundColor(.white)
Text("\(array.last![1][1])").foregroundColor(.white)
Text("\(array.last![1][2])").foregroundColor(.white)
Text("\(array.last![1][3])").foregroundColor(.white)
}
VStack {
Text("\(array.last![2][0])").foregroundColor(.white)
Text("\(array.last![2][1])").foregroundColor(.white)
Text("\(array.last![2][2])").foregroundColor(.white)
Text("\(array.last![2][3])").foregroundColor(.white)
}
VStack {
Text("\(array.last![3][0])").foregroundColor(.white)
Text("\(array.last![3][1])").foregroundColor(.white)
Text("\(array.last![3][2])").foregroundColor(.white)
Text("\(array.last![3][3])").foregroundColor(.white)
}
}
}
}
}
My toMaya.txt文件在下面等我调试目录：
file:///var/mobile/Containers/Data/Application/7C675F52-C78B-4252-98B5-3EBD37A3F832/Documents/toMaya.txt
之后您可以导出您的toMaya.txt文件到 Mac 使用UIActivityViewController.